1. Field of the Invention
This invention relates generally to the humidification of fibers, specifically cotton fibers in the form of lint, prior to baling of the cotton fibers at a cotton gin, and particularly to humidification by exposure of the cotton to warm humid air.
2. Description of the Prior Art
For years the desirability of humidifying cotton prior to baling it at the cotton gin has been recognized, and many attempts have been made to accomplish this end. There are several reasons for such humidification. Dry cotton is more difficult to press into a bale than is cotton of normal moisture content. This is particularly true now that cotton gins are producing the higher density "universal density" bales. After baling, dry cotton often breaks the steel straps which contain the bale, necessitating additional laber to replace such broken straps.
Probably the first systematic method of humidifying at the lint slide ahead of the baling press in a cotton gin was that of spraying the batt of cotton with a fine mist of liquid water to which a wetting agent had been added. This method was developed by the U.S. Government's Cotton Ginning Laboratory, at Stoneville, Mississippi, and was described by Charles A. Bennett in his article "Engineering Progress in Cotton Ginning" which appeared in the Cotton and Cotton Oil Press of Mar. 22, 1947. Apparatus employing this method is disclosed in U.S. Pat. No. 3,324,513, issued June 13, 1967, to D. B. Hurdt.
It has been common practice over the years to apply steam to the cotton at various points in a cotton ginning process. This method was especially popular when cotton gins were powered by steam engines and steam was readily available for this purpose. An example of steam humidification is described in U.S. Pat. No. 2,019,079, issued Oct. 29, 1935, to C. S. Herring.
At the present time, the most popular method of humidifying cotton at the gin involves exposing the cotton to warm humid air. This conditioning air is commonly generated by a device manufactured by the Samuel Jackson Manufacturing Corporation under the trademark "Humidaire", the corporation being controlled by the applicant herein. Such a unit comprises a direct-fired air heater, in which a gas fired burner operates with an open flame in the stream of air to be humidified. The stream of air is subsequently subjected to an air washer in which a recirculated water spray scrubs the heated air, simultaneously cooling the air and evaporating the water. The result is a supply of warm humid air of about 40.degree. to 60.degree. C dry bulb temperature and 70 to 100% relative humidity.
The humid air generated by the aforementioned humidifying unit has been applied in the feeders over the gin stands, in the conveyer distributor, in conditioning hoppers disposed between the conveyor distributor and the feeders, and in tower dryers. All the foregoing applications have as their object either the klling of state electricity or the lessening of damage to the cotton fibers during the ginning and lint cleaning processes. U.S. Pat. No. 2,312,557, issued Mar. 2,1943, to R. M. Joyce, discloses a method wherein cotton fibers are subjected to moist air conveyed into the stream of cotton in the lint flue as the stream of cotton emerges from the gin and prior to forming of the fibers into a batt of cotton.
In recent years, humid air has also been applied in the battery condenser of a cotton gin just ahead of the doffing rollers with the object of increasing the moisture content of the cotton fibers just prior to baling the ginned lint. See, for example, U.S. Pat. No. 2,815,536, issued Dec. 10, 1957, to W. R. Bryant. While this method accomplishes the purpose for which it is intended, it has certain disadvantages. In cold weather, moisture will sometimes condense on the condenser screen and cause it to "hair over" with a layer of cotton fibers which cannot be removed by the doffing rollers. Where the operation of the condenser is marginal, the introduction of additional air has also caused problems with forming a proper batt.
To avoid these difficulties, others have enclosed the lint slide down which the lint passes after leaving the battery condenser and introduced humid air through the lint slide cover. The humid air passes over the top of the cotton and exits through a screened opening elsewhere in the cover. Since it is difficult to make the humid air penetrate down into the cotton, this method has not found extensive use or success, except to maintain the moisture level achieved by humidification of the condenser.
Some years ago, I tried to humidify cotton by providing a small grid in the bottom of the lint slide, but the attempt was unsuccessful. The area of the grid was much too small and any significant flow of air blew the cotton out of the slide, with the result that it was impossible to raise the moisture content of the cotton by a measurable amount.